From: Felix Fietkau Date: Wed, 21 Aug 2013 20:59:25 +0000 (+0000) Subject: kernel: crashlog: Avoid out-of-bounds write X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=3848e6a246192d42160034e106f838b791931dce;p=openwrt%2Fstaging%2F981213.git kernel: crashlog: Avoid out-of-bounds write vsnprintf returns the number of chars that would have been written, not the actual number of chars written. This can lead to crashlog_buf->len being too big which in turn can lead to get_maxlen() returning negative numbers. The length argument of kmsg_dump_get_buffer will be casted to a size_t which makes a negative input a big positive number allowing kmsg_dump_get_buffer to write out of bounds. Fix this by using vscnprintf which returns the actually written number of chars. Signed-off-by: Helmut Schaa SVN-Revision: 37820 --- diff --git a/target/linux/generic/patches-3.10/930-crashlog.patch b/target/linux/generic/patches-3.10/930-crashlog.patch index 22778c04c7..4aba013eda 100644 --- a/target/linux/generic/patches-3.10/930-crashlog.patch +++ b/target/linux/generic/patches-3.10/930-crashlog.patch @@ -166,7 +166,7 @@ + return; + + va_start(args, fmt); -+ crashlog_buf->len += vsnprintf( ++ crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); diff --git a/target/linux/generic/patches-3.3/930-crashlog.patch b/target/linux/generic/patches-3.3/930-crashlog.patch index f6a52f3322..9a10723d76 100644 --- a/target/linux/generic/patches-3.3/930-crashlog.patch +++ b/target/linux/generic/patches-3.3/930-crashlog.patch @@ -166,7 +166,7 @@ + return; + + va_start(args, fmt); -+ crashlog_buf->len += vsnprintf( ++ crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); diff --git a/target/linux/generic/patches-3.6/930-crashlog.patch b/target/linux/generic/patches-3.6/930-crashlog.patch index 8c1a18a5db..88923993f3 100644 --- a/target/linux/generic/patches-3.6/930-crashlog.patch +++ b/target/linux/generic/patches-3.6/930-crashlog.patch @@ -166,7 +166,7 @@ + return; + + va_start(args, fmt); -+ crashlog_buf->len += vsnprintf( ++ crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); diff --git a/target/linux/generic/patches-3.8/930-crashlog.patch b/target/linux/generic/patches-3.8/930-crashlog.patch index da0d8008e4..4d0fc029d4 100644 --- a/target/linux/generic/patches-3.8/930-crashlog.patch +++ b/target/linux/generic/patches-3.8/930-crashlog.patch @@ -166,7 +166,7 @@ + return; + + va_start(args, fmt); -+ crashlog_buf->len += vsnprintf( ++ crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); diff --git a/target/linux/generic/patches-3.9/930-crashlog.patch b/target/linux/generic/patches-3.9/930-crashlog.patch index 867e5bb2f3..d20c32d0d7 100644 --- a/target/linux/generic/patches-3.9/930-crashlog.patch +++ b/target/linux/generic/patches-3.9/930-crashlog.patch @@ -166,7 +166,7 @@ + return; + + va_start(args, fmt); -+ crashlog_buf->len += vsnprintf( ++ crashlog_buf->len += vscnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args);